Process for treating oil shale



Man-ch12, 1929 J, UM L 1,704,956

PROCESS FOR TREATING OIL SHADE I Filed Sept. 1924 GOA/0544555.

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Patented Mar. 12, 1929.

UNITED STATES IILON J. TRUM'BLE, H LOS ANGELES, CALIFORNIA.

rnocnss r011 TREATING on. SHALE.

Application filed September 2, 1924' Serial No. 735,355.

My invention relates to the art of treating oil shale, and is particularly applicable to the destructive distillation of oil shale by means of superheated steam. v I

It is a well known fact that oil shale, in its natural state, contains substances which can .be Converted into-volatile hydrocarbons by the application of heatand pressure. It is an ob- 'ect of-my invention to provide an. apparatus y which this conversion can be accomplished.

Further objects and advantages of the mvcntion will be made evident hereinafter.

The annexed drawing is a diagrammatic representation partly in section of an apparatus adapted to carry on my process. In this apparatus I employ a preheater 1 which is placed in a spent shale receiver 2 and which is adapted to deliver shale into a retort 3. A dephlegmator 4 and a primary condenser 5 are provided, also a suction fan 6 and a secondary condenser 7.

In the form of apparatus shown, the preheater 1 consists of a tight shell 11 having a perforated top 12 and a discharge spout 13. A

filling neck 14 (hereinafter referred to as means for charging) is provided with a cover 15 and the discharge spout 13 is provided with a cover 16. A shield 17 is placed above the perforations in the to '12. The spent shale receiver surrounds t 1e preheater and consists of a shell 21 having a filling neck 22 (hereinafter referred to as means for charging) closed by a cover 23. A discharge spout 24 (hereinafter referred to as means for delivering shale from said heater to said retort) extends downwardly and is closed by a cover 25. Walls forming an air preheating cham ber 26 surround the spout 24,-the admission 4 of air tothe chamber 26 being controlled by a valve 27. Air is taken from the top of the air chamber 26 through a plurality of pipes 28 and is discharged into the spent shale receiver through slots 29, in the pipes 28.

' The retort 3 is provided with a filling neck 31 closed by a cover 32 and with a discharge spout 33 provided with a cover 34. The discharge spout 33 is so placed that it can readily discharge into a skip 35 which can be elevated as by a chain or rope 35 connected with a bail 35 to discharge into the filling neck 22 of the spent shale receiver 21 (and which is hereinafter referred to as means for delivering spent shale .from said preheater to said retort). The same skip (preferably provided with a fairly tight cover, not shown,to smother any flames spontaneously produced by momentary exposure of the hot spent shale, preferably handled above its ignition point, to the air) can be used to fill the preheater 1, if desired. The covers 32 and 34 can be made pressuretight and superheated steam maybe discharged into the interior of the retort 3 vided with an inlet pipe 61 which extends from and connects to the discharge spout 13 of the preheater 1, vapors being discharged from the pipe 6 into the condenser .7, which 1s of any standard type ofconstruction.

The method of operation of my invention is as follows:

The apparatus being charged with shale, the covers 32 and 34 are closed and superheated steam is delivered through the nozzle 36 into the mass of shale in the retort 3. The steam is preferably at or above 1000 degrees Fahrenheit and it acts upon the shale to raise it to a comparatively high temperature and to drive off the volatiles therethrough, these volatiles passing through the pipe 38 to the dephlegmator 4, and through the pipe 43 to the condenser 5. The condensates produced is one of the commercial products ofthe plant.

The preheater 1, being filled with raw shale, is given a preliminar treatment by means of hot spent shale in t e spent. shale receiver 2, the spent shale receiver having been charged by means of the skip 35 from the retort 3. The plate 17 prevents shale from clogging the openings 39 inthe perforated top 12. The spent shale at a high tempora ture completely surrounds the preheater 1 andtends to produce a preliminary distillation therein. Air being delivered through the valves 27 to the air heating chamber" 26 is "then injected into the spent shale in the spent shale receiver 2, through the openings 29 in the pipe 28. v

$pent shale ordinarily contains considerable quantities of free carbon or tar, and

p by the injection of air, a combustion is set i up. which further elevates the temperature of the spent shale and serves to heat the preheater 1. The gases of'combustion are also .drawn under the plate 17 and through the openings 39, downwardly through the raw shale in the preheater 1, by means of the pump 6 and the pipe 61. During the passage of the hot vapors through the shale, considerable distillations take place therefrom,

the products being condensed in the condenser 7.

It will be noted that my invention comv lprises the novel conception of utilizing the ot spent shale to preheat the raw shale before subjecting it to distillation in the retort 3. It also provides a novel conception' of accomplishing this preheating partly by ing the raw shale by passing hot spent shale in heat exchanging relationship, but out of contact with a body of the raw shale; distilling a body of the preheated shale by contacting therewith high] superheated steam; recovering volatile'pro ucts thus produced;

shale during the maintenance of the men, tioned heat exchanging relationship.

2. In the destructive distillation of oil shale, a process which comprises: preheating the raw shale by passing hot spent shale and burning residual carbon from said spent in heat-exchanging relationship, but out of contact with a body of the raw shale; dis" tilling a body of the preheated shale by contacting therewith highly superheated steam;

recovering volatile products thus produced;

and burning residual carbon from said spent shale during the maintenance of the mentioned heat exchanging relationship and pass- 5 ing the resultant roducts through said raw s ale.

In testimony whereof, I have hereunto set of combustion my hand at'Los Angeles, California, this 26th day of August, 1924.

MILON J. TRUMBLE. 

